The general aim of this project has been to improve electrical measurements of excitable membrane characteristics consistent with physical and chemical methods for the study of nerve membrane ionic channels. Two major approaches were used. The first involved the development of methods for rapid analysis of ionic channel conductances by means of computer controlled voltage clamp techniques. A new data acquisition system for controlling voltage clamp experiments on-line and acquiring excitable membrane conductance data in a form that can be analyzed by digital computing machines has been designed and constructed. Programs for carrying out this analysis were developed. The second approach involved analysis of excitable membrane characteristics by means of impedance measurements. Improvement of bridge impedance techniques to achieve greater accuracy were made. Impedance measurements on giant axons and an investigation of effects of polarizations for comparison with step and ramp techniques and ion conduction models were carried out. This project was supportive of a number of other projects in terms of the development of relevant hardware and software.